LOUISVILLE, Ky. (WDRB) – The Louisville-area stretch of the Ohio River and its tributaries is now under an advisory after potential harmful algal blooms were found in the river.

The warning, issued Friday by the Kentucky Division of Water and the Kentucky Department for Public Health, applies to people who fish, swim and boat on the river. Swallowing river water can cause skin, ear and throat irritation and increase nausea, vomiting and diarrhea.

Kentucky officials continue to extend the advisory westward since first alerting users of the river two weeks ago about the blooms, which are fed by excess nutrients and thrive in dry conditions and slow-moving water.

Earlier this week, the Division of Water observed blooms in at Cox Park and Harrods Creek and “significant” blooms near Madison, Ind., and downriver at West Point, Ky., according to a news release. Early test results found toxins that exceeded recommended levels in the Louisville area.

The advisory now includes all of the river from the West Virginia state line to the Cannelton Locks and Dam in Hancock County southwest of Louisville.

It doesn’t apply to drinking water from public water systems that draw from the river, such as the Louisville Water Company. Tests haven’t shown toxins in treated water from those utilities, according to the state.

Louisville Water officials have been monitoring the algae bloom as it’s moved down the river and recently added carbon to a reservoir at Crescent Hill, spokeswoman Kelley Dearing Smith told WDRB News this week.

“Carbon is really effective at absorbing taste and odor compounds, but also removing particles and toxins,” she said.

Near Cincinnati, organizers of a fundraising swim across the Ohio River have postponed their event until October because of the water conditions.

The Ironman triathlon, which includes a swimming segment on the river, is scheduled for Oct. 11 in Louisville. Phone calls to Ironman and the Louisville Sports Commission weren’t immediately returned Friday afternoon.

Copyright 2015 WDRB News. All rights reserved.